Transmission - Diff Shimming

OK, here's a really cool mod from 1100SHOTS from the Monster GT forum. The text in green below is from 1100SHOTS.

	If you find ANY flattened, chipped, or worn thin gear teeth on your pinion gear then JUNK IT! It is not uncommon to replace just the pinion gear. If your diffs make an occasional "popping" noise, chances are the ring gear is ok. If you have lost all drive from a diff, you may have stripped the internal gears, or the external (big) ring gear. Check them all.
	This pic shows the gear engagement between the pinion, and ring gears. This is a STOCK diff. As you can see, there is room for improvement with simple modifications, and some shimming. Having the gears line up, for 100% teeth mesh is essential for longevity.
	This is another view of stock diff with gears not engaging fully.

Quick & Easy Diff Shim

The ring/pinion mesh takes a helluva beating, as all the stresses of acceleration and deceleration are absorbed by one or two tiny teeth.Virtually all of us have heard the dreaded diff clicking sound. That’s the sound you hear when your ring/pinion mesh has basically been ground away. Chances are good, when you remove the diff housing and take it apart, you will see metal shavings inside. That metal used to be part of the ring and pinion gears.Here’s a very easy and quick way to shim the pinion gear. This moves the pinion gear further into the ring gear for a more positive mesh. The goal with this mod is to eliminate all the slop, but NOT make it so tight that it binds.

What You Need

Here are the shims you need to move the pinion out:

	These are the 8 x 10 x .02 shims. Here's a link to order them from Tower: http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXGPC9&P=7 These are only $2.89 for a whole pack.
	Many times, Tower is out of the above shims. If that's the case, then you can use these shims instead: http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXJVD0&P=7 These are $4.79 for a pack.

The Process...

Step 8 assumes you have used two shim washers, totaling about .016 thickness. If you have used only one washer, then you would shorten drive cup accordingly.

I (Chevy-SS) also use the GPM case tighteners:

I think 1100SHOTS and I both agree that the main problem area in the diffs in the ring/pinion mesh. Simply do that mod to your diffs and they should last a good, long time.

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